Blood clots can be a frightening and severe health issue for cats. Known medically as thromboembolism, blood clots in cats often occur suddenly and can lead to life-threatening conditions. One of the most common forms of blood clot in cats is aortic thromboembolism (ATE), often referred to as a “saddle thrombus.” This condition is a medical emergency that requires immediate veterinary attention. Let’s explore what blood clots are, why they occur in cats, the signs to look out for, and whether these clots are survivable.

What Causes Blood Clots in Cats?

In cats, blood clots are usually associated with underlying health issues, particularly heart disease. One of the most common heart conditions linked to clot formation is hypertrophic cardiomyopathy (HCM). HCM causes the heart muscle to thicken, which can lead to changes in blood flow within the heart. These changes increase the likelihood of clot formation, which can then travel through the bloodstream and lodge in arteries, obstructing blood flow to vital organs.

Other causes that can contribute to clot formation include:

• Hyperthyroidism: An overactive thyroid gland can alter blood circulation, raising the risk of clots.

• Kidney Disease: Chronic kidney disease can affect blood pressure and heart function, increasing clot risk.

• Cancer: Certain types of cancer can create a state of hypercoagulability, making the blood more likely to clot.

While blood clots can occur in various parts of the body, the most common and concerning location for clots to lodge is the aorta, the main artery that carries blood from the heart. When a clot blocks blood flow at the aortic bifurcation (the point where the aorta splits to supply the hind legs), it results in what is known as a “saddle thrombus.”

Recognising the Signs of a Blood Clot in Cats

The onset of symptoms is often sudden and alarming. Cats with an aortic thromboembolism may exhibit:

• Sudden paralysis or weakness in the hind legs: This is the most typical sign and occurs because the clot prevents blood flow to the legs.

• Cold limbs: The affected limbs may feel noticeably colder than the rest of the body.

• Severe pain: Cats with ATE are usually in significant pain and may vocalise or exhibit signs of distress.

• Difficulty breathing: If the clot impacts blood flow to the lungs, the cat may have laboured breathing or panting.

• Bluish paw pads: Due to the lack of oxygenated blood reaching the hind limbs, the paw pads may appear bluish or grey.

These symptoms should be treated as an emergency. Immediate veterinary intervention is crucial for any chance of survival.

Can Cats Survive Blood Clots?

The prognosis for cats with blood clots, particularly aortic thromboembolism, is often guarded. However, survival is possible, especially if the underlying cause is identified and managed. Key factors influencing the cat’s chance of survival include:

• Severity of the clot: The size and location of the clot can significantly affect the outcome. Smaller clots that partially block blood flow may have a better prognosis.

• Underlying health conditions: Cats with manageable conditions, such as controlled heart disease, may have a more favourable outcome than those with multiple severe health issues.

• Treatment approach: Prompt and aggressive treatment, including pain management, blood thinners, and supportive care, is essential. In some cases, surgical removal of the clot may be considered.

Treatment Options for Cats with Blood Clots

The primary goals of treatment for cats with blood clots are to alleviate pain, restore blood flow, and address the underlying cause. Treatment typically includes:

• Pain relief: Providing strong pain relief is a priority, as ATE is extremely painful.

• Blood thinners: Medications such as heparin or clopidogrel may be used to reduce blood clotting and prevent further clot formation.

• Supportive care: Intravenous fluids, oxygen therapy, and other supportive measures may be provided to stabilise the cat.

• Surgery: In some cases, surgery may be performed to remove the clot, although this is not always feasible or successful.

Despite treatment, recurrence is common, as cats with underlying heart disease or other predisposing conditions remain at risk for further clots.

Preventing Blood Clots in Cats

Preventing blood clots involves managing the underlying health conditions that predispose cats to clot formation. For cats diagnosed with heart disease, regular veterinary check-ups and medication to manage heart function can significantly reduce the risk of clot formation. Additionally, medications like blood thinners may be prescribed for at-risk cats to prevent future clots.

Living with a Cat Prone to Blood Clots

Having a cat with a history of blood clots or underlying heart disease requires a proactive approach to health management. Be vigilant about monitoring your cat for any signs of distress, pain, or changes in mobility. Early intervention is key to improving your cat's chances of recovery if a clot does occur.

Conclusion

Blood clots in cats, particularly aortic thromboembolism, are a serious medical condition that can have life-threatening consequences. While the prognosis can be poor, survival is possible with prompt treatment and ongoing management of underlying health issues. As a pet owner, being aware of the signs and seeking immediate veterinary care can make a significant difference in your cat’s outcome.

References:
For more information on blood clots in cats, visit Vet Help Direct.